GB2201974A

GB2201974A - Monitoring device for flat knitting machines

Info

Publication number: GB2201974A
Application number: GB08804592A
Authority: GB
Inventors: Ernst Goller; Fritz Walker
Original assignee: H Stoll GmbH and Co KG
Current assignee: H Stoll GmbH and Co KG
Priority date: 1987-03-10
Filing date: 1988-02-26
Publication date: 1988-09-14
Also published as: GB8804592D0; JPS63227846A; ES2006064A6; FR2612208A1; CH674219A5; DE3707569A1; IT1215772B; IT8819190A0; US4799365A; JPH0217662B2

Description

z; . 1 - Monitoring Device for Knitting Machines 2'0 197 r.

z t The present invention relates to a monitoring device for monitoring knitwear being taken down from a flat bed knitting machine, the device having at least one sensing lever which is supported, on a support body adjustable in longitudinal direction of the needle beds on a rail, which lever rests against the knitwear which is pre-tensioned below the needle beds and which is coupled to an arm which can actuate an electric switching device.

Devices of the type mentioned above are known in which the actuating arm of each sensing lever act.; on a separate microswitch which is connected via a cable to the control device of the flat bed knitting machine and, when actuated by the arm, closes or opens a control circuit. The cables are provided with a plug connector so that sensing levers which are not be used for monitoring can be disconnected from the control device. The cable connections have been found to be very obstructive in the operation of the machine, particularly when reinserting knitting which has dropped off. Since the cable connections must be kept relatively long because of the adjustability of the support structure for the sensing levers, the risk also exists there that cabes which have been unplugged and not sufficiently - k secured drop downwards and are picked up by a delivery device or winding- up device for the knitwear.

Sensing levers are also known which are adjustable over the entire length of the needle beds and which are rigidly coupled to an arm which, in an activating position of the sensing lever, rests against a conductor which is exposed (but insulated mounted) and which is common to the sensing levers, thus to close a control circuit. Although the cable connections are omitted in this design, problems occur with sensing levers which are not intended to be used for monitoring. Such sensing levers must be either completely removed or displaced into special parking areas in which the conductor is insulated so that the switching arms of the sensing levers placed out of operation cannot form a contact bridge. This adjustment jof the sensing lever support bodies arranged below the needle beds represents an annoying additional operation in an area of the machine which cannot be easily subjected to a visual check.

An object of the invention is to develop a monitoring device in which separate switching-off or adjusting of sensing levers which are not intended to be used for monitoring can be dispensed with.

According to the invention there is provided a monitoring device for monitoring knitwear being taken down from a flat 0 1 z 1 1 1 - 3 bed knitting machine, the device having at least one sensing lever which is supported on a support body adjustable in the longitudinal direction of the needle beds on a rail, which lever rests against the knitwear which is pre-tensioned be low the needle beds and which iscoupled to an arm which can actuate an electric switching device, the arm being constructed as a contactless contactor which is movable through an operative connection of the electric switching device into an ineffective end position in response to movement of the sensing lever.

Thus, the device according to the invention has the advantage that a sensing lever can trigger a switching pulse, that is to say close or open a control circuit, with its switching arm only during its response movement, but no longer influences the electric switching device, in its end position which it assumes when the knitwear is not present. Thus, sensing levers exempted from monitoring the knitwear can remain in their response position, do not need to be electrically decoupled and also do not need to be displaced into areas which are ineffective for control purposes. There are no cable connections to the support bodies of the feeling levers.

The operative connection for the electric switching device can be advantageously formed by a light beam or barrier (infra-red light beam) or ultrasonic beam, which is common j k - 4 to several sensing levers, through which the switching arm of a monitoring sensing lever moves when the knitted fabric is taken down and quells a short-term interruption of the contact barrier which is sufficient to trigger,a control signal. However, sensing levers with individual switching devices can also be used, in which each feeling lever support body is provided, for example, with a Hall generator which can be influenced during the contactless passage of the switching arm and which can be connected via slip contacts to conductors formed on the rail so that here, too, there is no cable connection to the individual sensing lever support bodies.

The switching arm can be suitably drive-coupled to the sensing lever with transmission of movement in such a manner that the switching arm executes a longer distance of movement than the sensing lever. In a preferred embodiment, the switching arm is constructed as a two-armed tilting lever, supported on the adjustable support body, having arms of different lengths, the shorter arm of which is engaged by the sensing lever and the end area of the longer arm of which forms the contactor which can be moved through the contact range of the associated switching device. In this arrangement, the sensing lever is suitably held under spring tension against the knitwear and the switching arm is suitably held under spring tension in the direction of its ineffective end position.

1 11 The invention will now be described further by way of example with reference to the accompanying drawings in which:

Figure 1 is a diagrammatic front view of a flat bed knitting machine with the front needle bed partially removed and having several monitoring elements arranged below thC.- needle bed; and Figure 2 is a cross-section through the needle beds of the knitting machine on a scale which is enlarged with respect to that of Figure 1, and in the case of a flat-bed knitting machine provided with a knitwear delivery device.

Referring now to Figure 1 a machine frame is designated 10, a carrier 11 for the front needle bed 12, a machine carriage 13 and a bobbin stand 14 arranged above the bed. The carrier 11 and the front needle bed 12 are partially removed so that the needle gap knitwear delivery area 15, located below the two needle beds can be seen in which a device for monitoring the knitted fabric or fabrics 16 is arranged.

The monitoring device has several wide sensing levers 17 which are each arranged on a support 18 which, according to figure 2, is displaceably mounted on a rail 19 which is attached to a carrier 20 for the needle bed 22 and extends R k - 6 over the entire length of the two needle beds 12 and 22. According to Figure 2, each sensing lever 17 is inserted in a holder 21 which is supported to be rotatable about an axis 23 on the support body 18 and which is pre-tensioned by a tension spring 24.

In addition, a switching arm 25 is rotatably supported about an axis 26 on the support 18, which arm is pivoted intermediate its length with the shorter alarm at a point 27 on the holder 21 and which forms a contactless contactor with the longer arm.

The sensing lever 17 and the switching arm 25 are drawn with continous lines in the position which they assume when the sensing lever does not rest against a length of knitwear 16' and in which the sensing lever 17, and thus also the switching arm 25, are pre-tensioned by the tension spring 24. The sensing lever 17 is drawn with dot-dashed lines in the position which it assumes when resting against a length of knitwear 16' which is being delivered to a take-up roller 29. In this monitoring position of the sensing lever 17, the switching arm 25 assumes the position also drawn with dot-dashed lines in Figure 2.

With the angular range limited by the two positions of the switching arm 25 drawn, an infra red light beam 30 extends beween a light transmitter 31, drawn in Figure 1, and a -1 1 - 7 11 light receiver 32. The infra red light beam 30 forms the contact range of a switching device, not shown in greater detail, of a control device of the flatbed knitting machine. Duringthe adjusting movement of the switching arm 25 from its one end position into the other and vice versa, the light beam is interrupted for brief time, but is not influenced in the end positions of the switching arm 25, even in its end position drawn with continous lines which it assumes with the sensing lever 17 unloaded. This ineffective end position is assumed, for example, by switching lever 25 of the sensing lever 171, drawn fully on the left in Figure 1, which is arranged in the needle area free of knitwear.

The monitoring elements constructed in accordance with the invention with their sensing lever 17 and a switching arm 25 constructed as a contactless contactor can also be coupled to individual switching devices which can consists of a Hall generator which is arranged in the support body and which can be influcenced by the switching arm 25 during its adjusting movement and which can be coupled via slip contacts to electric contact tracks of the control device which are formed on the rail 19.

Claims

CLAIMS:

1. A monitoring device for monitoring knitwear being taken down from a flat bed knitting machine, the device having at least one sensing lever which is supported on a support body adjustable in the longitudinal direction of the needle beds on a rail, which lever rests against the knitwear which is pre-tensioned below the needle beds and which is coupled to an arm which can actuate an electric switching device, the arm being constructed as a contactless contactor which is movable through an operative connection of the electric switching device into an ineffective end position in response to movement of the sensing lever.

2. A monitoring device as claimed in Claim 1 in which the operative connection for the switching device is formed by a light barrier or ultrasonic barrier which is common to the or each sensing lever.

3. A monitoring device as claimed in Claim 1, in which the or each support body of a sensing lever is provided with a Hall generator which is influenced upon displacement of the arm and which is connected via slip contacts to conductors formed on the rail.

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4. A monitoring device as claimed in any one of Claims 1 to 3 in which the arm is drive-coupled to the sensing lever in such a manner that for a given displacement, the arm executes a longer distance of movement than the sensing lever.

5. A monitoring device as claimed in any one of Claims 1 to 4, in which the arm is constructed as a two-armed tilting lever, supported on the adjustable support body, having arms of different lengths, the short arm of which is engaged by the sensing lever and the end area of the long arm of which forms the contactor which can be moved through a contact range of the associated switching device.

6. A monitoring deivce as claimed in any one of Claims 1 to 5 in which the sensing lever is spring loaded against the knitwear and the arm is spring loaded in the direction of its ineffective end position.

7. A monitoring device as claimed in Claim 2 or any claim appendant thereto in which the light barrier extends parallel to the rail over the entire length of a needle bed.

8. A monitoring device for monitoring knitwear being taken down from a flat bed knitting machine substantially as herein described with reference to and as illustrated in the accompanying drawings.

Published 1988 at The Patent Offtce, State House, 86171 High Holborn, London WC1R 4TP. Purther copies may be obtained from The Patent OffLoe,